Bridging "Islands" of Wilderness a Boon to Animals

Even if the habitats are not contiguous, said Wollf, "stepping stone" habitats can provide sanctuaries in which members of different populations can mingle. For woodland patches to serve as stepping stones for red squirrels, they must be within a mile (1.5 kilometers) of one another.

Wollf's work has broad implications for land management. It lends considerable support to attempts to resurrect the habitat of endangered species by rejoining their fragmented territories. For example, one goal of the Wildlife Conservation Society of the United States is to link jaguar habitat from Arizona to Argentina.